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Patented Dec. lid, 1%29 stares STANLEY L. WILLIS AIQ'D WATSGN H. Vi 083E631), OF BREDGEPOBT, CGNNECTECUT, AS- SIGNORS TO REMIETGTOElARMS COMPANY, ENG, A CORPUS-5318K OF DELAWARE VTATEEPROOFING This invention relates to the manufacture of water-proof. paper shot shells and is desi ned as an improvement over the process described in the U. S. Patent :f,'r'1,130,303, issued March 2, 1915, to Lindsay and Hibbard.

In the manufacture of paper tubes for shot shell bodies, the tube is formed from a sheet of paper, it being the usual practice to roll such a sheet into tubular form and secure it with a suitable adhesive. After bein thus formed and pasted, the'tubes are dried and lubricated, then they are polished, and brought to the desired size by passing through suitable sizing dies. This operation is known as sizing the tube and the term sizing as used in this specificationrefers to this operation. Either before or after sizing the tubes are, finished by treating with molten paraffin or other waxes, the was or a mixture of waxes and mineral oil, to a certain extent filling the pores of the paper.

The patent to Lindsay and Hibbard above identified, describes an improved waterproofing process comprising the, application to the unslzed tubes of a polymerizable Oll, or

a mixture including a polymerizable oil and a lubricating oil carried in a volatile vehicle such as carbon tetrachloride. The composition disclosed in said patent as well as. other waterproofing coinpesitions which have been applied to shot shelltubes prior to the present invention and of which a polynerizable oil is an essential constituent, have all been applied to the unsized tubes. It will be understood that it has always been considered necessary to have any compositions which included China wood oil applied before sizing in order that it might be properly spread, and the tube properly and Application filed "ll/lay 12,

1925. Serial No. 29,797.

smooth uniform finish. W'hile polymerizable il alone is satisfactory, a composition including a polymerizable oil as one of its constituents gives excellent and readily controlled results. For example, acomposition which has been found very desirable comprises a polymerizable oil and one of the class of substances wn as driers, the general effect of the presenceof these substances being to facilitate oxidation. A volatile carrier or solvent say be added for the purpose of decre 1g the thickness of the film of the composition which adheres to the shell. A preferred method of preparing such a composition is as follows:

A mixture comprising the polymerizable oil and the drier in suitable proportions is prepared and heated to a temperature which is empirically determined, and will of course, vary with the particular polymerizable oil and the particular drier used and with their proportions. The appro r iate uant the volatile solvent is addedto the heated mixture. After cooling, a small quantity of polymerizable oil may be added, as it has been found that such an addition serves to retard the drying of the oil and insures a thinner, smoother, and more perfect film.

One composition which has been used with very satisfactory results comprises Chinese wood oil, and a drier of lian szjanese resinate and lead oxide (litharge) digested in carbon tetrachloride, and is prepared as follows: is. mixture comprising about thirtyseven parts of Chinese wood oil, one part of manganese resinate, and eightparts of lead oxide, is heated and maintained at a temperature of about 220 C. for about 10 minutes. Ninety-five parts of c rbon tetrachloride are then added and the composition is allowed to cool. After cooling a small quantity of the Chinese wood oil is added. This typical formula, however, may be greatly varied. Any polymerizable oil may he used and likewise any suitable drier. For example, we have socured excellent results with driers of lead tungate, lead resinate, or cobalt tungate. Likewise any suitable volatile fluid may be used as a thinner or solvent. Excellent results have been secured with such thinners as gasoline, kerosene, or turpentine. The present invention is not limited, however, to any of the substances named, it being the essence of this discovery that a polymerizable oil, or a composition comprising a. polymerizable oil, a suitable drier and a suitable thinner, may be applied at any stage in the manufacture of the shells with superior waterproofing results and without affecting the size of the shells.

After the application of the polymerizable oil, or the polymerizable oil compound, the oil is gelatinized by any suitable means, such as heat, air, chemical agents, or gases. If the polymerizable oil alone is used, heat gelatinization is desirable, while for the compositions which have been described, air drying for periods up to about five hours is preferable.

It is, of course, well known that the use of polymerizable oils and compositions including polymerizable oils for waterproofing various substances including certain kinds of paper, has been practiced hitherto, but the compositions and processes which have been used are inapplicable to the manufacture of shot shell tubes, on account of the problems which are peculiar to this art, one such problem being the diificulty of obtaining a smooth outside surface. By the present invention a composition comprising a polymerizable oil as an essential constituent has for the first time been successfully applied to sized tubes and this invention will be claimed broadly. in the appended claims the term sized tubes is to be understood as including tubes in any stage of the shell manufacturing proc ess, subsequent to sizing.

We claim:

1. The method of waterproofing paper tubes for cartridge shell bodies which comprises treating the sized tubes with a composition comprising a polymerizable oil and a drier heated and digested in a volatile solvent, and having asmall quantity of polymerizable oil added thereto subsequent to cooling.

2. The method of waterproofing paper tubes for cartridge shell bodies which comprises treating the sized tubes with a composition comprising Chinese wood oil, a drier of manganese resinate and lead oxide heated to about 220 C. and digested in carbon tetrachloride, and having a small quantity of Chinese wood oil added thereto, subsequent to cooling.

3. The method of waterproofing paper tubes for cartridge shell bodies which comprises treating the sized tubes with a composition comprising 37.5 parts of Chinese wood oil, one part of manganese resinate, and eight parts of lead oxide, heated to about 220 C. and digested in ninety-five parts of carbon tetrachloride, and having a small quantity of Chinese Wood oil added thereto, subsequent to cooling.

' 4. A waterproofing composition for paper cartridge shell bodies comprising a polymerizable oil and a drier of manganese resinate and lead oxide digested in a suitable volatile solvent.

5. A waterproofing composition for paper cartridge shell bodies comprising a polymer izable oil and a drier of magnanese resinate and lead oxide digested in carbon tetrachloride.

6. A waterproofing composition for paper cartridge shell bodies comprising Chinese wood oil and a drier of manganese resinate and lead oxide digested in carbon tetrachloride.

7. A waterproofing composition for paper cartridge shell bodies comprising 37.5 parts of Chinese wood oil, one part of manganese resinate, and eight parts of lead oxide, digested in ninety-five parts of carbon tetrachloride.

8. A waterproofing composition for paper cartridge shell bodies comprising Chinese wood oil and a drier of manganese resinate and lead oxide heated together and digested whil heated, in carbon tetrachloride.

9. A waterproofing composition for paper cartridge shell bodies comprising Chinese wood oil and a drier of manganese resinate and lead oxide heated together and digested while heated,in carbon tetrachloride, and having a small quantity of Chinese wood oil added thereto, subsequent to cooling.

10. A Waterproofing composition for paper cartridge shell bodies comprising 37.5 parts of Chinese wood oil, one part of manganese resinate, and eight parts of lead oxide, heated together to about 220 C., and digested while heated, in ninety-five parts of carbon tetrachloride, and having a small quantity of Chinese wood oil added thereto, subsequent to cooling.

11. The method of preparing a waterproofing composition for paper cartridgeshell bodies comprising heating a polymerizable oil and a drier together to partially polymerize the oil and While heated digesting the same in a volatile solvent.

STANLEY L. WILLIS. WATSON H. TVOODFORD.

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